It doesn't matter. You don't need to send it in becuase you are already CERF clear according to my mentor. No one needs to send in the form and register to be CERF clear.
You don't necessarily need to send the form in, as most puppy buyers won't ask to see if, and you know it was a good exam. You have good exams in the past to prove it as well.
But if you do want to have it re-registered with CERF, just call the Doctor and have them copy their form and send it to you.
Your mentor is giving you incorrect advice. The Canine Eye Registration Foundation (CERF) provides eye "registration" certificates for dogs that have met the criteria required for their breed. A normal exam by a diplomate of the American College of Veterinary Ophthalmologists (ACVO)is just that - an exam - and is usually documented on a CERF form. If the form is not sent to CERF with the appropriate fee, then the dog is NOT CERF certified. It might be accurate to say that the dog is ACVO normal (or clear) if there were no notations on the exam form. Of course, if you don't have a copy of the form, it is just your word. See the thread labeled "Research" for more on people who just "say" their dog is tested without any proof.
The simple solution is to request a copy of the exam form from the ACVO who examined the dog.